Rock drill



W. A. SMITH Jan. 13, I931.

ROCK DRILL Filed April 11, 1928.

INVENTOYR. mllimu 1.6112111:

H15 ATTORNEY Patented Jan. 13, 1931 UNITED STATES PATENT OFFICE WILLIAM A. SMITH, OF PHILLIPSBURG, NEW JERSEY, ASSIGNOR TO INGERSOLL-RAND COMPANY, OF JERSEY CITY, NEW JERSEY, A CORPORATION OF NEW JERSEY ROCK DRILL Application filed April 11,

This invention relates to rock drills, but more particularly to an oiling device for fluid actuated rock drills of the hammer e. One object of the invention is to supply an adequate amount of lubricant to the wearing surfaces of the elements comprising the rock' drill.

Other objects will be in part obvious and in part pointed out hereinafter.

In the drawings in which similar reference characters refer to similar parts,

Figure 1 is a longitudinal sectional elevation of a rock drill having the invention applied thereto, and

Figure 2 is a longitudinal elevation partly broken away of the rearward end of the drill.

Referring more particularly to the drawings, A designates a cylinder having a bore B, an intermediate ortion of which forms a piston chamber B in which is disposed a reciprocatory hammer piston C. The cylinder has a free exhaust port A which is controlled by the piston. A back head D is seated on the rearward end of the cylinder and at the front end of the cylinder A is disposed a front head E. The cylinder A, the back head D and the front head E in this instance comprise the casing of the rock drill and these parts may be held in assembled relationship by means of the usual spring pressed side bolts (not shown).

A closure is provided for the front end of the cylinder in the form of a bushing F which extends into the cylinder and has a forwardly extending sleeve portion G which acts as a wearing surface for a chuck H insorted in the front head E to receive a working implement J. Preferably the sleeve portion G of the bushing is provided with a lateral flange K near its front end to lie between the adjacent ends of the front head E and the cylinder A.

In the construction shown, the working implement J is of the type which is adapted to be interlocked with a chuck H and thus alsoto be rotated in unison with the chuck for the purpose of changing the position of the drill steel preparatory to the delivery of 1928. Serial No. 269,267.

The usual spring pressed pawls P are car'- ried by the rifle bar Lto engage a rotation ratchet Q, inserted in this instance in the rearward end of the cylinder A. The rota;

tion mechanism, such as the rifle bar and its adjuncts, are preferably of a well known type and a detailed description thereof is therefore considered unnecessary.

Formed integrally with the front end of the piston C is an extension or nose R which extends slidably through a bore S in the bushing F and is provided with longitudinal flutes T to slidably engage-ribs U carried by a chuck nut V in the rearward end of the chuck H.

A closure for the rearward end of the piston chamber B is provided in the form of a back cylinder washer W through which the rifle bar L extends. A plate X also disposed in the rearward end of the cylinder is seated on the back cylinder washer W. In the plate X is formed a valve chamber Y for the reception of a distributin valve Z which controls the distribution 0 pressure fluid from the chamber Y to the front and rearward ends of the piston chamber through passages. b and 0 respectively. Both passages 12 and 0 are formed in the back cylinder washer W and the passage 1) opens into a passage (1 in the cylinder which in turn communicates-with the front end of the cylinder through a port e.

For illustrative purposes the distributing valve Z is shown as being of the oscillatory plate type and disposed about the rifle bar L. It is, however, to be understood that the present invention is not limited to the particular type of valve described or to its precise location, but that the invention is applicable to any type of rock drill as well as valve mechanism.

In the back head D is a throttle valve 7 having a central bore 5: into which pressure fluid from a suitable source of supply may be introduced. The throttle valve f is of the rotatable type and controls the admisratchet Q, the

sion of pressure fluid into the drill. The throttle valve f accordingly has a port h in its periphery which in the open position of the valve registers with a passa e is leading through the back head D, t e rotation late X and opens into the valve chamber In drills, such as the type illustrated in which a multiplicity. of movable parts are employed, it is at times dlifiicult to introduce lubricant in suitable quantities to the wearing surfaces of the parts. One method frequently employed to introduce lubricant into the drill is to interpose an air line oiler into the pressure supply pipe and convey oil in an atomized state through the medium of the pressure fluid into the rock drill.

As may be readily appreciated, this method has its limitations, since lubricant is conveyed only to those parts of the drill into which pressure fluid is introduced. Other means are therefore required for lubricating the wearing surfaces of parts into which pressure fluid does not have access.

The present invention contemplates the introduction of lubricant to all wearing sur faces of the rock drillelements and in a manner to assure ample lubrication without flooding any portion of the rock drill and consequently wasting the lubricant as well as causing van undesirable spray of oil to issue from the exhaust port A of the cylinder. To this end an annular chamber is formed in the periphery of the bushing F to form a reservoir 0 for lubricant, such as oil. The oil may be introduced into the reservoir 0 through an opening p in the cylinder A normally sealed by a filler. plug 9 In the outer surface of the bushing F and forwardly and rearwardly of the reservoir 0 are formed annular grooves 1' and 8 respectively. These grooves communicate with the reservoir through assages t in the bushing F. In the wall 0 the cylinder A are formed small passages to and 1; which register with the grooves r and s and open into a passage w extending rearwardly through the wall of the cylinder A. The passage 'w communicates with the passage is through a passage 0: which in this instance also communicates with the throttle valve f through a passa e y formed in the rotation ratchet and the ack head;

The function of the passages m, w, e, and t is to convey pressure fluid into the reservoir 0 during the open position of the throttle valve f. Owing to the remoteness of the reservoir 0 from the source of pres sure fluid supply, a pressure only will be created on the oil in the reservior so that during the operation of the drill no lubricant will be conveyed from the reservoir through these passages.

The presence of pressure fluid in the res- Q ervoir causes oil to be forced through re stricted annular spaces A between the cooperating surfaces 2 and 2 of the bushing F and the cylinder A respectively, both in a forwardly and rearwardly direction. The amount of such oil depends, of course, upon the amount of clearance between the surfaces 2 and 2 which. determines the areas of the spaces A Preferably, however, the clearance forming the spaces A is of small extent so that oil in only such quantities may pass therethrough as may be required to assure thorough lubrication of the coop erating surfaces of the movable elements located forwardly of the bushing F.

At a point forwardly of the groove 7'- and in the periphery of the sleeve portion of the bushing F is an annular groove 3 which may encircle the sleeve portion G to intercept oil moving in a forwardl direction through the front space A' uch oil is conveyed from the annular groove 3 through radial passages 4 into the interior of the sleeve portion G to lubricate the chuck H. Preferably a longitudinal groove or grooves 5 are formed in the periphery of the chuck H to assure the distribution of the lubricant along the entire surface of the chuck. In the construction shown, passages 6 are formed in the periphery of the sleeve portion G and communicate with the annular groove 3 to avoid the necessity of forcing the oil for a considerable distance against resistance.

In order to convey oil from the reservoir 0 to the rifle bar L, a passage 7 is formed in the cylinder and communicates with an annular groove 8 in the rearward end of the bushing F through a small passage 9. The groove 8-is located rearwardly of the groove 8, but preferably in close proximity thereto, so that oil from the groove may be forced through the rear space A into the groove 8. Near the rearward end of the passage 7 is a port 10 which leads through the cylinder A and the back cylinder washer W to a bore 11 in the back cylinder washer through which the rifle bar L extends. A groove 14 may be formed in the throttle valve to register with the passage 3 in the closed position of the throttle valve f.

In the construction shown, means, such as a water tube 12, are provided for conveying water from the back head through the drill and the working implement J for the purpose of cleansing the drill hole. In order to augment the pressure of the water thus utilized a passage 13 is formed in the back head D, the cylinder A and the bushing F for conveying pressure fluid from the throttle valve to the bore S in the bushing. At this point the pressure fluid flows through the flutes T and thence through the chuck H into the drill steel J.

The manner in which the lubricant is dis rious passages due to the cut-off and admission of pressure fluid will not be effective to convey oil from the reservoir into the passage is during the operation of the drill. The pressure acting on the oil in the reservoir 0 will, however, force oil both in a rearwardly and forwardly direction through the spaces A The oil flowing in a forwardly direction between the cylinder and the bushing F will "be intercepted by the groove 3 and will flow from said groove through the passages 4 against the peripheryof the chuck H which, as will be readily understood, is intermittently rotated due to the action of the rifle bar L and associated elements. The oil delivered to the surface of the chuck H may advance in a forwardly direction through the passage 5 in the chuck H so that the entire exterior surface of the chuck as well as the cooperating surfaces of the bushing and the front head will be thoroughlylubricated throughout their lengths.

During the admission of pressure fluid into the rearward end of the piston chamber B for impelling the piston C forwardly against the working implement J, a portion of the pressure fluid utilized for this purpose will flow along the rifle bar into the passage 10, thence through the passages 7 and 9 into the annular groove 8 where it mingles with the oil. s the piston uncovers the exhaust port A, the pressure fluid in the rearward end of the piston chamber B will, of course, be exhausted to the atmosphere. At the same time the pressure fluid in the passages leading from the bore 11 to the groove 8 will also flow into 'the bore 11 against the rifle bar L and deposit a spray of lubricant on the rifle bar suflicient to maintain the wearing surfaces of the rifle bar and those of the rifle nut O in a thoroughly lubricated state. The admission of pressure fluid into the groove 8 in this instance occurs only on alternate strokes of the piston and preferably during the admission of pressure fluid into the rear end of the piston chamber B to drive the piston forwardly.

Whenever it is desired to stop the operation of the drill, as for instance, for the purpose of changing drill steels, the throttle valve f may e rotated to the closed posi-,

tion in Figure 2. In this position the groove 14 in the throttle valve is brought into registry with. the passage y. When the throttle valve is moved to the closed osition, the pressure fluid which had een acting on the oil in the reservoir will of course exhaust through the passages connecting the reservoir with the valve chamber Y. Such pressure fluid will carry with it a suitable quantity of oil which is deposited into the valve chamber. A certain portion of oil will also flow through the passage 3/ into the groove '14; to lubricate the throttle valve f. The lubricant deposited in the valve chamber Y may remain therein until the drill is again set in operation, whereupon the oil is blown from thevalve chamber Y into the piston chamber B to thoroughly lubricate the piston and the cooperating surfaces of the cylinder.

In ractice'the present invention has been foun to be unusually efiicient. It permits of a thorough and efiicient distribution of the lubricant in accordance with the requirements of the several elements of the drill.

I claim:

1. In an oiling device for rock drills, the combination of a cylinder and chuck mechanism rotatable relatively to the cylinder, a bushing in the cylinder having a chamber forming an oil reservoir and cooperating with the cylinder to form a restricted space between the contiguous surfaces of the cylinder and the bushing, a passa e leading from a source of supply constant y conveying pressure fluid into thereservoir to force oil from the reservoir through the space and passages in the bushing forwardly of the reservoir for conveying such oil into the chuck mechanism.

2. In an oiling device for rock drills, the combination of a cylinder and chuck mechanism rotatable relatively to the cylinder, a bushing in the cylinder having a chamber forming an oil reservoir and cooperating with the cylinder to form a restricted annular space forwardly of the reservoir, a passage leading from a source of supply constantly conveying pressure fluid into the reservoir to force oil from the reservoir through the annular space, an annular groove in the bushing to intercept such oil, and passages in the bushing for conveying oil from the annular groove to the chuck mechanism.

3. In an oiling device for rock drills, the combination of a cylinder having a bore and chuck mechanism rotatable relatively to the cylinder, a reciprocatory piston in the cylinder, a bushing in the bore having an annular chamber to serve as an oil reservoir and being of slightly smaller diameter than the bore to form an annular space therebetween, a passage leading from a source of supply constantly conveying pressure fluid into the reservoir to force oil through the annular space, an annular groove in the bushing to intercept such oil, and a passage in the cylinder to admit pres sure fluid into the annular groove for conveying oil therefrom into the cylinder.

4. In an oiling device for rock-drills, the combination of a cylinder and chuck mechanism rotatable relatively to the cylinder, a reciprocatory piston in the cylinder, a bushing in the cylinder having an annular chamber forming an oil reservoir, a passage leading from a source of supply constantly conveying pressure fluid into the reservoir to force oil therefrom between the cooperating surfaces of the bushing and the cylinder, an annular groove in the bushing to intercept such oil, and a assage in the cylinder to intermittently a mit pressure fluid into the annular groove for conveying oil therefrom into the cylinder.

5. In an oiling device for rock drills, the combination of a cylinder and chuck mechanism rotatable relatively to the cylinder,

a reciprocatory piston in the cylinder, a

bushing in the cylinder having an annular chamber forming an oil reservoir, a passage leading from a source of supply constantly conveying pressure fluid into the reservoir to force oil therefrom between the cooperating surfaces of the bushing and the cylinder, an annular groove in the bushing to intercept such oil, and a passage leading from one end of the cylinder to the annular groove through which pressure fluid pulsates on each alternate stroke of the piston for conveying oil from the annular groove into the cylinder.

6. In an oiling device for rock drills, the combination of a cylinder and chuck mechanism rotatable relatively to the cylinder, a reciprocatory piston in the cylinder, a bushing in the cylinder having an annular chamber forming an oil reservoir, a passage leading from a source of supply constantly conveying pressure fluid into the reservoir to force oil therefrom between the cooperating surfaces of the bushing and the cylinder, an annular roove in the bushing to intercept such oi, and a passage leading from the rearward end of the cylinder to the annular groove through which pressure fluid pulsates on each forward stroke of the piston for conveying oil from the annular groove into the cylinder.

7. In an oiling device for rock drills, the combination of a cylinder and a piston in the cylinder, chuck mechanism interlocked slidably with the iston, a rifle bar slidably interlocked with t e piston for rotating the chuck mechanism, a bushing in the cylinder having a chamber forming an oil reservoir, a passage in the cylinder, constantly conveying pressure fluid into the reservoir to force oil from the reservoir between the surfaces of the bushing and the cylinder during. the operation of the drill and to convey-oil from the reservoir into the c linder upon stoppin of the drill, annu ar rooves in the bus ing to intercept oil orced from the reservoir, passages in the bushing for conveying oil from one groove to the chuck mechanism, and a passage in a the cylinder through which pressure fluid ulsates into another annular groove durmg each alternate stroke of the piston for conveyin oil to the rifle bar and the rearward en of the cylinder.

8. Inan oiling device for rock drills, the combination of a cylinder and a piston in the cylinder, chuck mechanism interlocked slidably with the piston, a rifle bar slidably interldcked with the piston for imparting rotary movement to the chuck mechanism, a valve chest having a valve chamber, a valve in the chamber controlling the distribution of pressure fluid into the cylinder, a throttle valve controlling the admission of pressure fluid into the valve chamber, a bushing in the cylinder having a chamber forming anv oil reservoir, a passage leading from the throttle valve and conveying pressure into the reservoir for forcing Oll between the cooperating surfaces of the bushing and the cylinder during the operation of the drill and for conveying oil to the cylinder, the

valve chamber and the throttle valve upon closing of said throttle valve, annular rooves in the bushing to intercept oil forced between the bushing and the cylinder, a passage in the bushing for conveying oil from one groove into the chuck mechanism, and a assage in the cylinder for conveying oil rom another groove to the rifle bar and into the cylinder.

In testimony whereof I have signed this specification.

WILLIAM A. SMITH. 

